Grate structure



Oct. 22, 1929. w. B. CHAPMAN GRATE STRUCTURE Filed March 28. 1927 lll/l j :B Zaza- 5 INvx-:Nron )i/ill iam Cha/00mn ATT Y Patented Get. 22, 1929 UNITED STATES PTE "FFICE eltern STRUCTURE Application- 'filed March 28, 1927'. Serial No. 179,915.

My invention relates to furnaces of heating plants, power plants and other furnaces in which subbituminous coal is burned. My object is to provide a grate structure for use in suoli furnaces which Will enable the fireman to obtain a quick response and secure an even control of the heat. A specific object is to provide a partition grate to divide the fire box into compartments side by side, the number of partition grates used depending on the number of compartments desired, so that when each alternate coinpartaient is filled With coal, fire can be kindled in each remaining compartment and l5 said fire allowed to eat its Way into the fuel in the filled compartments.

The properties of subbituininous coal, such as is mined in Colorado and adjoining States, are such that the best results in fir- S'J ing are obtained when fire s allowed to eat its Way into a pile of coal from the sides. llolring and stirring the coal is detrimental to the best results. For this reason I'have provided the partition grate Which Will nonT be described.

Figure l, denotes a cross sectional plan of a furnace containing my partition grate,

taken on the line A--A iii Fig. 2; Fig. 2,

a. vertical cross section of the furnace on 3o the line lil- B in 3; Fig. 3, a vertical cross section on the line C-G in Fig. 2; Fig. 4f, a fragmentary cross section in elevation of a furnace showing a modified form of partition grate, and Fig. 5, a detail view of a support.

Although I show' the preferred embodinient of my invention, I do not thereby limit myself to the precise form shown, but Wish it uneerstood that Within the scope of what hereinafter is claimed various changes in the details of construction may be made,

Without departingr from the spirit of the invention.

The reference character l denotes the shell of a furnace suoli as is commonly used in het air heating plants; 2, the fire box wall; 3, the ash pit, and l the door. The horizontally disposed grate comprises bars 5, G, 7, 9, l0 and 1l, provided With trid angular members 12 and mounted in the fire box wall 2. bar (l and me on bar?. A

AV cog Wheel 13 is mounted on shed With cog wheel lll mounted siinilarcog Wheel 15 is mounted on bar 9 and meshed With cog Wheel 16 mounted on bar l0. lIhe partition grate with bars 22 which terminate so as to vforni an arch over the triangular members ncct bars l? and 17d;`

fr plurality of bars 17h con- The modification shown in Fig. fl, comprises a bai' 24 mounted in lugs 9.5, and aplurality of bars 2G ex tending dow nward from bar 24. and terminating so as to form an arch.

ln the drawings I have shown the fire box divided into fire boxes of two compartments, but With large grate areas I advise the use of my partition grates to divide the lire box into a larger number of compartments tnat each compartment will be of the proper size to facilitate firing by theinethod described. The functi on of the arched portion in this grate structure is threefold as follows: The

e. frangenient design is suc of the partition as ivell as its h that the unburiied portion of the fuel remaining in the fire pot is separated from the burning portion of the fuel by this paritioii, thereby permitting the fuel which is in a finely divided state,`to burn only in a gradual manner, this manner of coniubstion then approaches that of solid fuel, or fuel i pose of the u lump forni, this being the purgrate. The arched opening in the partition mentioned above is to permit the gradual completely li that is burnin()r feeding of the fuel from the lled side of the grate to the side g, or burned out, thereby allowing a continuous combustion from one side of the p artition to the other as the case might be. This arched opening, after having allowed the passage of a portion of the finely divided fuel from the filled side Of the partition to the side that is burning, forms a means of communication for the fire between filled side.

the burned out side of the grate and the It allows the fire to progress from one side of the grate to the other in order that the firing ma be maintained continuously by means of ring alternate sides of the grate. It must'be kept in mind that this grate structure Was designed primarily for the combustion of finely divided or powdered fuels.

A campartment, as E, is filled with coal to the top of the partit-ion grate. A fire is then kindled'in compartment D. The fire in compartment D then eats its Way under the arch and through other openings in the partition grate and consumes the coal in compartment E. When the fuel in compartment E has been reduced to a bed of live coals7 compartment D is filled with fuel and the fire in comparment E eats its Way into the pile of fuel in compartment D and reduces it to a bed of live coals. after Which compartment D isl refilled. This alternate filling of the compartments is kept up indefinitely. It will be knoted that the coalis allowed to burn Without poking or other disturbance except the shaking down of the ashes.

The ashes are shaken from compartment D by turning bar 7 Which carries cog Wheel 14 engaging cog Wheel 13. This action turns bars 6 and 7 with their triangular members 12, and shakes down the ashes into ash pit 3. The ashes are shaken from compartment vE by turning bar 9, Which carries cog Wheel 15 meshed With cog Wheel 16.

VIn fire boxes of large area Where several partition grates are used to divide the fire box into a number of compartments side by side, each alternate compartment is filled with coal and a fire is kindled in each remaining compartment so that the fires Will eat into the fuel in the adjacent filled compartments.

Iclaim:

1. A grate of the class described comprising standards; tWo outside bars and a. middle bar connecting said standards; triangular grate members on one of said outside bars; bars extending from Said middle bar yand terminating so as to form an arch over said triangular grate members; and bars spaced from each other connecting the remaining outside bar with said middle bar.

2. A great of the class described comprising standards; main bars connecting said standards, one of said main bars being provided With a plurality of triangular grat-e members, and another one of said main bars being provided with a plurality of secondary bars extending therefrom and terminating so as to forman arch over said triangular grate members.

3. In combination with a fire box, a vertically disposed grate mounted in said fire box, said grate comprising vertically disposed standards; horizontally disposed main bars connecting saidrstandards; triangular grate members on one of said main bars; and a 

